Kotlin-android: unresolved reference databinding

I have following fragment class written in Java using the new databinding library

import com.example.app.databinding.FragmentDataBdinding;

public class DataFragment extends Fragment {

    @Nullable
    private FragmentDataBinding mBinding;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        mBinding = DataBindingUtil.inflate(inflater, R.layout.fragment_data, container, false);
        return mBinding.getRoot();
    }
}

It compiles and runs fine.
I tried to rewrite it in Kotlin and came up with the following:

import com.example.app.databinding.FragmentDataBdinding

class ProfileFragment : Fragment() {

    private var mBinding: FragmentDataBinding? = null

    override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        mBinding = DataBindingUtil.inflate(inflater, R.layout.fragment_data, container, false)
        return mBinding!!.getRoot()
    }
}

But now step :app:compileDebugKotlin outputs the following:

Error:(16, 38) Unresolved reference: databinding
Error:(37, 27) Unresolved reference: FragmentDataBinding

How can I use android-databinding library with Kotlin?

My top-level build.gradle:

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.3.0'
        classpath 'com.android.databinding:dataBinder:1.0-rc4'
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

My build.gradle in app dir (only relevant parts):

apply plugin: 'com.android.application'
apply plugin: 'com.android.databinding'
apply plugin: 'kotlin-android'

dependencies {
    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
}

buildscript {
    ext.kotlin_version = '0.14.451'
    repositories {
        mavenCentral()
    }

    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath "org.jetbrains.kotlin:kotlin-android-extensions:$kotlin_version"
    }
}
repositories {
    mavenCentral()
    maven {
        url 'http://oss.sonatype.org/content/repositories/snapshots'
    }
}

I'm using Android Studio 1.4, Build tools version 23.0.1, Android SDK 23, SDK tools 24.4.0

Try use this configuration:

In main build.gradle:

buildscript {
    ext.kotlin_version = '<kotlin-version>'
    ext.android_plugin_version = '2.2.0-alpha4'
    dependencies {
        classpath "com.android.tools.build:gradle:$android_plugin_version"
    //... rest of the content
    }
}

App build.gradle:

android {
    dataBinding {
        enabled = true
    }
}

dependencies {
    kapt "com.android.databinding:compiler:$android_plugin_version"
}

kapt {
    generateStubs = true
}

I found new solution, hope it will helps you.

First of all check whether plugin applied:

apply plugin: 'kotlin-kapt'

then

android {
    ...
    ...
    dataBinding {
        enabled = true
    }
    ...
    ...
}

You might have an error in dependency:

USE

kapt 'com.android.databinding:compiler:3.1.4'

instead of

compile 'com.android.databinding:compiler:3.1.4'

You can visit here for new version

Thank you.

And use layout tags in layout file before using its binding class , you can easily do that : In layout file your root view (e.g.- Constraint Layout) ALT+Enter -> convert to data binding class

Update 2: This is a really old answer, instead refer to lrampazzo's answer.

It works with 1.0-rc4, put

kapt 'com.android.databinding:compiler:1.0-rc4' 

into your dependencies

Thanks Ghedeon, for the link in comments

Update: Here's a really simple hello world example project

The version of Data Binding compiler is same as gradle version in your project build.gradle file:

// at the top of file 
apply plugin: 'kotlin-kapt'


android {
  dataBinding.enabled = true
}

dependencies {
  kapt "com.android.databinding:compiler:3.0.0-beta1"
}

and the gradle version is

classpath 'com.android.tools.build:gradle:3.0.0-beta1'

Here is an example link to complete using of databinding library in kotlin.

https://proandroiddev.com/modern-android-development-with-kotlin-september-2017-part-1-f976483f7bd6

In my case, this solved my problem.

I added this in the app build.gradle:

buildFeatures {
    dataBinding true
    viewBinding true 
}